view tests/test-merge10.t @ 25732:b94df10cc3b5

hghave: allow adding customized features at runtime

Before this patch, there is no way to add customized features to
`hghave` without changing `hghave` and `hghave.py` themselves.

This decreases reusability of `run-tests.py` framework for third party
tools, because they may want to examine custom features at runtime
(e.g.  existence of some external tools).

To allow adding customized features at runtime, this patch makes
`hghave` import `hghaveaddon` module, only when `hghaveaddon.py` file
can be found in directories below:

  - `TESTDIR` for invocation via `run-tests.py`
  - `.` for invocation via command line

The path to the directory where `hghaveaddon.py` should be placed is
added to `sys.path` only while importing `hghaveaddon`, because:

  - `.` may not be added to `PYTHONPATH`

  - adding additional path to `sys.path` may change behavior of
    subsequent `import` for other features

`hghave` is terminated with exit code '2' at failure of `import
hghaveaddon`, because exit code '2' terminates `run-tests.py`
immediately.

This is a one of preparations for issue4677.

Test for changeset 9fe267f77f56ff127cf7e65dc15dd9de71ce8ceb
(merge correctly when all the files in a directory are moved
but then local changes are added in the same directory)

  $ hg init a
  $ cd a
  $ mkdir -p testdir
  $ echo a > testdir/a
  $ hg add testdir/a
  $ hg commit -m a
  $ cd ..

  $ hg clone a b
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd a
  $ echo alpha > testdir/a
  $ hg commit -m remote-change
  $ cd ..

  $ cd b
  $ mkdir testdir/subdir
  $ hg mv testdir/a testdir/subdir/a
  $ hg commit -m move
  $ mkdir newdir
  $ echo beta > newdir/beta
  $ hg add newdir/beta
  $ hg commit -m local-addition
  $ hg pull ../a
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg up -C 2
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge
  merging testdir/subdir/a and testdir/a to testdir/subdir/a
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg stat
  M testdir/subdir/a
  $ hg diff --nodates
  diff -r bc21c9773bfa testdir/subdir/a
  --- a/testdir/subdir/a
  +++ b/testdir/subdir/a
  @@ -1,1 +1,1 @@
  -a
  +alpha

  $ cd ..